I have a house of similar age and replaced all the knob and tube wiring myself with metal-clad cable when I bought it. There were no functional issues with the old wiring and honestly I kind of regret stripping away that part of the house’s history, but there were two reasons I did it:
I wanted to be able to walk through the attic space without fear of death if I tripped and landed in such a way that I’d be touching both wires
and
The unshielded wires that were a foot or two apart from each other put off a significant amount of EMF interference compared to modern wiring, especially the metal-clad type that I was using.
That said, knob and tube does hold up better in many circumstances to wiring that’s just a little bit newer by virtue of the fact that the wires are physically distant from each other. Some of the early insulation on stuff that pre-dates Romex (or, for all I know, Romex as well if you were to age it 100 years) can eventually fail and then you’ve got two wires contacting each other.
